Role of adipose tissue grafting and adipose-derived stem cells in peripheral nerve surgery

Abstract

The application of autologous fat grafting in reconstructive surgery is commonly used to improve functional form. This review aims to provide an overview of the scientific evidence on the biology of adipose tissue, the role of adipose-derived stem cells, and the indications of adipose tissue grafting in peripheral nerve surgery. Adipose tissue is easily accessible through the lower abdomen and inner thighs. Non-vascularized adipose tissue grafting does not support oxidative and ischemic stress, resulting in variable survival of adipocytes within the first 24 hours. Enrichment of adipose tissue with a stromal vascular fraction is purported to increase the number of adipose-derived stem cells and is postulated to augment the long-term stability of adipose tissue grafts. Basic science nerve research suggests an increase in nerve regeneration and nerve revascularization, and a decrease in nerve fibrosis after the addition of adipose-derived stem cells or adipose tissue. In clinical studies, the use of autologous lipofilling is mostly applied to secondary carpal tunnel release revisions with promising results. Since the use of adipose-derived stem cells in peripheral nerve reconstruction is relatively new, more studies are needed to explore safety and long-term effects on peripheral nerve regeneration. The Food and Drug Administration stipulates that adipose-derived stem cell transplantation should be minimally manipulated, enzyme-free, and used in the same surgical procedure, e.g. adipose tissue grafts that contain native adipose-derived stem cells or stromal vascular fraction. Future research may be shifted towards the use of tissue-engineered adipose tissue to create a supportive microenvironment for autologous graft survival. Shelf-ready alternatives could be enhanced with adipose-derived stem cells or growth factors and eliminate the need for adipose tissue harvest.

Bioengineering approaches for nerve graft revascularization: Current concepts and future directions

“…When appropriately stimulated by the microenvironment, stem cells can influence vascularity via cell‐to‐cell communications, differentiation, and release of VEGF, making them ideal for vascularization of tissue‐engineered constructs (Hong et al, 2010; Rehman et al, 2004). Of the various MSCs, adipose‐derived mesenchymal stem cells (ADSCs) have been extensively studied for enhancement of nerve graft vascularization, due to its ease of harvest (via minimally invasive techniques such as liposuction), superior stem cell fraction, pluripotency, and ease of in vitro expansion and proliferation (Saffari et al, 2022). ADSCs facilitate angiogenesis directly by differentiating into vascular endothelium and indirectly via endogenous SC expression of growth factors such as nerve growth factor (NGF), brain‐derived neurotrophic factor (BDNF), and VEGF (Erba et al, 2010; Rhode et al, 2021).…”

“…ADSCs facilitate angiogenesis directly by differentiating into vascular endothelium and indirectly via endogenous SC expression of growth factors such as nerve growth factor (NGF), brain‐derived neurotrophic factor (BDNF), and VEGF (Erba et al, 2010; Rhode et al, 2021). ADSCs can also regulate the ECM to promote tissue regeneration and scar tissue reduction (Dong et al, 2020; Saffari et al, 2022). An in vitro study demonstrated that ADSCs seeded onto ANA increased mRNA and protein expression of neurotrophic and angiogenic factors, such as BDNF and VEGFa (Rbia et al, 2019).…”

CORR Insights®: Do Liquid Nitrogen–treated Tumor-bearing Nerve Grafts Have the Capacity to Regenerate, and Do They Pose a Risk of Local Recurrence? A Study in Rats

“…It is important to assess the revascularization and regeneration of decellularized tumor-bearing nerve grafts treated with liquid nitrogen [1-3, 5, 6, 9]. The local cell population—for example, the number of Schwann cells, fibroblasts, intraneural fibrosis, and vascularity density—is important in order to evaluate regeneration capabilities.…”

“…The local cell population-for example, the number of Schwann cells, fibroblasts, intraneural fibrosis, and vascularity density-is important in order to evaluate regeneration capabilities. Adipose-derived stem cells, vascular endothelial growth factor, or fat tissue composite grafts have been reported to promote regeneration of nerve grafts [1,2,5,6]. Finally, longerterm observation of nerve grafts would provide data about integrity maintenance, functional outcomes, and late sequelae such as neuroma, neuropathic pain, and paresthesia [3,7,9].…”

Global Analyses and Latest Research Hot Spots of Adipose-Derived Stem Cells in Fat Grafting: A Bibliometric and Visualized Review

“…Autologous fat grafting is one of the most effective and safest technique in reconstructive surgery to promote functional and esthetic form [ 1 ]. It has several advantages such as accessibility to adipose tissue, inexpensive, non-immunogenicity and biocompatibility.…”